Compass saw



c. H. RAINES El AL 2,123,471

COMPASS SAW Filed NOV. 22, 1957 INVENTORS C. H. R mas J. C. RA\NE$ ATTORNEY.

Patented Aug. 30, 1938 UNITED STATES COMPASS SAW Claude n. Raines, Portland, and James 0. mu, Lacomb, Oreg.

Application November 22, 1937, Serial No. 175,864

1 Claim.

This invention relates generally to cutting tools, and particularly to a compass saw for forming angular cuts.

The main object of this invention is the construction of an improved form of compass saw by means of which square holes may be sawed and in which one portion of the saw forms a guide for another portion thereof.

The second object is the provision of a saw of the class described in which two saws are mounted on one handle and are held in a fixed annular relationship and in which a guide is interposed between the adjacent ends of the sawing edges.

The third object is to so construct the saw that it will be easy to manufacture and maintain and that there will be no danger of mutilating the sides of the cut formed by one portion of the saw due to an excessive movement of the saw.

The fourth object is to provide a limiting stop which will prevent the joint action of two portions of the saw within the same out.

These and other objects are accomplished in the manner set forth in the following specification as illustrated in the accompanying drawing, in

which:

Fig. 1 is a perspective view showing a form of the device in which the auxiliary blade is formed along the back edge of the saw.

Fig. 2 is a fragmentary section taken along the line 2-2 in Fig. 1.

Fig. 3 is a perspective view of a blade showing an auxiliary cutting element formed along the same side of the blade as is the main cutting element.

Fig. 4 is a fragmentary view showing the manner in which the right angle cut is being formed in a board.

Fig. 5 is a fragmentary view showing the action of the stop.

Fig. 6 is a fragmentary plan of the auxiliary cutting element.

Similar numerals refer to throughout the several views.

5 Referring in detail to the drawing, there is shown in Figs. 1 and 2 a compass saw blade ill whose shank H is provided with a slot l2 for attachment to a handle (not shown). The shank II is somewhat wider than is the main body of 50 the blade Ill and is provided with a shoulder l3 which servesas a stop for limiting the sawing action of the teeth I! on the blade Hi.

In this form of the device, there is formed an auxiliary blade l5 along the back Hi. The blade 5 I5 is in this instance normal to the shank ll.

similar parts The teeth l'l merge into the shank II at the point l8 which is nearer to the slot l2 than is the shoulder l3.

In the form of the device shown in Fig. 3, the blade ill-A is provided with teeth lB-A 6 which terminate at the stop l3-A. In this form of. the device the shank l l-A is provided with the auxiliary cutting blade l5-A whose teeth l|-A merge with the shank ll-A at the point l8-A which is spaced from the shoulder li-A. 0

The two forms of the device are identical except that in the form shown in Figs. 1 and 2, the teeth of the two saws are on opposite edges of the blade III while in the form shown in Fig. 3 the two sets of cutting edges are on the same side 15 of the saw.

When the saw, as shown in Fig. 1, is used, the cut is started by means of the teeth I4 and the movement of the blade I0 is limited by the shoulder IS. The saw is then taken out of the cut 20 and turned so that the back l6 guides along the end of the cut l9 and as the saw is operated, the teeth I! form the new cut 20 which is normal to the cut IS.

The action of the saw illustrated in Fig. 3 25 is identical except that the blade |0-A' need not be withdrawn. It is merely necessary to move the teeth IG-A away from the end of the cut I! far enough to pass the stop l3--A and permit the edge 2| to guide the saw while the teeth ll-A are forming their portion of the out.

It can be seen that with this construction it is possible to form square holes in materials and that these operations may be performed quickly and accurately with a minimum amount of ef- 35 fort. Obviously, other angles may be formed for special purposes if desired, the square being merely illustrative.

Numerous attempts havebeen made to produce saws of this type, examples of which are shown 40 in the patent of Weymar, No. 416,281, and Allen 72,582. These devices, however, never found their way onto the market for several reasons.

First, they were difficult to construct. Second, they were diflicult to operate satisfactorily because of the fact that the cutting teeth of the auxiliary blade merged with the cutting teeth of the main blade, so that no guiding action for the auxiliary blade was obtained from the main blade. Furthermore, unless the operator was extremely careful, the auxiliary blade would continually mar the sides of the slot formed by the main blade. All of these defects are overcome by our present invention in which the guiding portions 2| or the portion of the back l6 which ing cutting teeth formed between said stop and the point of said blade, a guide formed on said saw extending from said stop away from the point of said saw and in parallelism with its cutting teeth and an awnliary'saw blade integral with said main blade and normal thereto having its cutting teeth merging into the end of said guide which is spaced from said stop.

CLAUDE H. JAMES 0. W138. 

